There are a LOT of DVD burners out there that are either DVD-R *OR* DVD+R (note the plus and minus because it's very significant) but *NOT BOTH*. Make absolutely sure that if it's a DVD+R drive that you're using DVD+R media and not even DVD+RW (not all drives will support RW media) or DVD-R or DVD-RW.
You might also want to make sure that it's a DVD burner and not just a DVD-ROM/CD-RW combo drive, because those will not burn DVDs, only CDs.
If none of the above applies, try looking for a firmware update for the drive. Some 2X DVD burners have problems with 4X media which is usually addressed in a firmware update.
If all else fails, jump through the hoops Dell wants you to, and keep insisting that they replace the drive if it fails all attempts to get it working. They will likely be rather reluctant to do this, but really have no choice under the warranty agreement that comes with the laptop. Just keep at it, and if necessary, keep asking for the person's superior until you find someone who can help you.
My roomate recently got this laptop with a DVD writer in it but hadn't used it up until this point. However we can't figure out why it won't read the dvd+rs at all. We are using FujiFilm DVD+Rs but the drive doesn't recognize that a dvdr is even in the drive. Either using nero, or a few other dvd progs, windows doesn't even recognize a disc. I have already run diagnostics and gone through some crap with dell, but to no avail. btw its a inspiron 5150. Thanks

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